Dr. Jean-Claude Bouret Profile

Dr. Jean-Claude Bouret

at Lab d'Astrophysique de Marseille

SPIE Involvement:

Author

Publications (8)

Proceedings Article | 13 December 2020 Poster + Paper

MAVIS: science case, imager, and spectrograph

Simon Ellis, Richard McDermid, Giovanni Cresci, Christian Schwab, Francois Rigaut, Timothy Chin, Robert Content, Anthony Horton, Mahesh Mohanan, Helen McGregor, Jacob Pember, David Robertson, Lew Waller, Ross Zhelem, Stephanie Monty, Trevor Mendel, Matteo Aliverti, Guido Agapito, Simone Antoniucci, Andrea Balestra, Andrea Baruffolo, Maria Bergomi, Andrea Bianco, Marco Bonaglia, Guiseppe Bono, Jean-Claude Bouret, David Brodrick, Lorenzo Busoni, Elena Carolo, Simonetta Chinellato, Jess Cranney, Gayandhi De Silva, Simone Esposito, Daniela Fantinel, Jacopo Farinato, Thierry Fusco, Gaston Gausachs, James Gilbert, Damien Gratadour, Davide Gerggio, Marco Gullieuszik, Pierre Haguenauer, Dionne Haynes, Visa Korkiakoski, Demetrio Magrin, Laura Magrini, Luca Marafatto, Benoit Neichel, Fernando Pedichini, Enrico Pinna, Cedric Plantet, Elisa Portaluri, Kalyan Radhakrishnan, Roberto Ragazzoni, Bernado Salasnich, Stefan Ströbele, Elliott Thorn, Annino Vaccarella, Daniele Vassallo, Valentina Viotto, Frédéric Zamkotsian, Alessio Zanutta, Hao Zhang

Proceedings Volume 11447, 11447A0 (2020) https://doi.org/10.1117/12.2561930

KEYWORDS: Imaging systems, Spectrographs, Visible radiation, Adaptive optics, Stars, Galactic astronomy, Image quality, V band, Spectral resolution, Spatial resolution

Read Abstract +

Proceedings Article | 13 December 2020 Poster + Presentation + Paper

Precision requirements for the POLLUX-LUVOIR spectropolarimeter

Eduard Muslimov, Jean-Claude Bouret, Coralie Neiner, Marc Ferrari, Simona Lombardo, Arturo Lopez Ariste, Maëlle Le Gal

Proceedings Volume 11444, 114446G (2020) https://doi.org/10.1117/12.2559873

KEYWORDS: Spectral resolution, Manufacturing, Ultraviolet radiation, Space observatories, Spectrographs, Polarimetry, Holography, Wave propagation, Wavefronts, Cameras

Read Abstract +

Proceedings Article | 9 September 2019 Presentation

Opening the road to custom astronomical UV gratings (Conference Presentation)

Fabien Grise, Randall McEntaffer, Nicholas Kruczek, Kevin France, Eduard Muslimov, Jean-Claude Bouret, Amandine Caillat, Brian Fleming

Proceedings Volume 11119, 111190Z (2019) https://doi.org/10.1117/12.2530350

KEYWORDS: Ultraviolet radiation, Astronomy, Roads, Holography, Silicon, Ions, Stray light, Spectrographs, Diamond, Metallic coatings

Read Abstract +

Historically, ultraviolet (UV) gratings used in astronomical spectrographs have been made using two different techniques. Mechanically-ruled gratings have been produced for more than an hundred years. A diamond tool is used to create parallel grooves onto a fine metallic coating layer that has been previously deposited on a polished substrate. The edge-on profile of these grooves is a sawtooth tilted at a specific angle called the "blaze" angle. The blaze angle is the deciding factor that will allow for maximum efficiency at a specific wavelength called the "blaze" wavelength. Holographic gratings are produced using interference lithography. A layer of photoresist deposited on a substrate is exposed to fringes usually formed by exposure to two coherent laser beams. After development, the resulting pattern is sinusoidal by nature. Blazing one side of the sinusoidal profile of holographic gratings is possible through ion etching, but is only commonly used for a limited subset of grating parameters. Both types of gratings have different advantages: - Ruled gratings have a sharp, blazed profile that ensures good efficiency. However, they suffer from groove spacing inconsistencies that lead to stray light and ghosting. - Holographic gratings do not suffer from groove spacing errors which minimizes stray light. However, their sinusoidal profile (if not ion etched) leads to efficiency losses. At Penn State University, we are studying new processes that allow to fabricate blazed, high efficiency and high spectral resolution UV gratings for astronomical purposes. These processes are derived from the ones we used in creating X-ray gratings and consist of: - writing an electron-beam pattern consisting of parallel grooves on a layer of positive resist that has been deposited on a Si substrate. - dry etching this profile into a hard mask made of silicon nitride. - wet etching with KOH that will create the sawtooth profile at a specific blaze angle thanks to the properties of the different crystallographic planes of silicon. Gratings fabricated using these techniques show an excellent behavior all around, combining the best qualities from both ruled and holographic gratings. Indeed, they display a sharp sawtooth profile, they do not suffer from periodicity errors, and grating facets show low roughness. Recent testing show efficiencies that are close to the maximum, theoretical limit. Combined with the possibility to create custom blaze angles through the use of custom cut Si wafers, this opens the way to new applications in the field of astronomical UV spectroscopy.

Proceedings Article | 16 August 2019 Presentation

Opening the road to custom astronomical UV gratings (Conference Presentation)

Fabien Grise, Randall McEntaffer, Nicholas Kruczek, Kevin France, Eduard Muslimov, Jean-Claude Bouret, Amandine Caillat, Brian Fleming

Proceedings Volume 10958, 109580X (2019) https://doi.org/10.1117/12.2515108

KEYWORDS: Ultraviolet radiation, Astronomy, Roads, Holography, Silicon, Ions, Stray light, Spectrographs, Diamond, Metallic coatings

Read Abstract +

Historically, ultraviolet (UV) gratings used in astronomical spectrographs have been made using two different techniques. Mechanically-ruled gratings have been produced for more than a hundred years. A diamond tool is used to create parallel grooves onto a fine metallic coating layer that has been previously deposited on a polished substrate. The edge-on profile of these grooves is a sawtooth tilted at a specific angle called the "blaze" angle. The blaze angle is the deciding factor that will allow for maximum efficiency at a specific wavelength called the "blaze" wavelength. Holographic gratings are produced using interference lithography. A layer of photoresist deposited on a substrate is exposed to fringes usually formed by exposure to two coherent laser beams. After development, the resulting pattern is sinusoidal by nature. Blazing one side of the sinusoidal profile of holographic gratings is possible through ion etching, but is only commonly used for a limited subset of grating parameters. Both types of gratings have different advantages: - Ruled gratings have a sharp, blazed profile that ensures good efficiency. However, they suffer from groove spacing inconsistencies that lead to stray light and ghosting. - Holographic gratings do not suffer from groove spacing errors which minimizes stray light. However, their sinusoidal profile (if not ion etched) leads to efficiency losses. At Penn State University, we are studying new processes that allow to fabricate blazed, high efficiency and high spectral resolution UV gratings for astronomical purposes. These processes are derived from the ones we used in creating X-ray gratings and consist of: 1) writing an electron-beam pattern consisting of parallel grooves on a layer of positive resist that has been deposited on a Si substrate. 2) dry etching this profile into a hard mask made of silicon nitride. 3) wet etching with KOH that will create the sawtooth profile at a specific blaze angle thanks to the properties of the different crystallographic planes of silicon. Gratings fabricated using these techniques show an excellent behavior all around, combining the best qualities from both ruled and holographic gratings. Indeed, they display a sharp sawtooth profile, they do not suffer from periodicity errors, and grating facets show low roughness. Recent testing done at UC Boulder shows efficiencies that are close to the maximum, theoretical limit. Combined with the possibility to create custom blaze angles through the use of custom cut Si wafers, this opens the way to new applications in the field of astronomical UV spectroscopy.

SPIE Journal Paper | 18 December 2018

Design and modeling of spectrographs with holographic gratings on freeform surfaces

Eduard Muslimov, Marc Ferrari, Emmanuel Hugot, Jean-Claude Bouret, Coralie Neiner, Simona Lombardo, Gerard Lemaitre, Robert Grange, Ilia Guskov

OE, Vol. 57, Issue 12, 125105, (December 2018) https://doi.org/10.1117/12.10.1117/1.OE.57.12.125105

KEYWORDS: Optical design, Diffraction gratings, Holography, Spectrographs, Diffraction, Spectral resolution, Optical engineering, Reflection, Image quality, Ray tracing

Read Abstract +

Proceedings Article | 6 July 2018 Paper

The science case for POLLUX: a high-resolution UV spectropolarimeter onboard LUVOIR

Jean-Claude Bouret, Coralie Neiner, Ana I. Gómez de Castro, Chris Evans, Boris Gaensicke, Steve Shore, Luca Fossati, Cécile Gry, Stéphane Charlot, Frédéric Marin, Pasquier Noterdaeme, Jean-Yves Chaufray

Proceedings Volume 10699, 106993B (2018) https://doi.org/10.1117/12.2312621

KEYWORDS: Ultraviolet radiation, Stars, Polarization, Magnetism, Galactic astronomy, Planets, Polarimetry, Spectral resolution

Read Abstract +

Proceedings Article | 6 July 2018 Presentation + Paper

POLLUX: a UV spectropolarimeter for the LUVOIR space telescope project

Eduard Muslimov, Jean-Claude Bouret, Coralie Neiner, Arturo López Ariste, Marc Ferrari, Sébastien Vivès, Emmanuel Hugot, Robert Grange, Simona Lombardo, Louise Lopes, Josiane Costeraste, Frank Brachet

Proceedings Volume 10699, 1069906 (2018) https://doi.org/10.1117/12.2310133

KEYWORDS: Mirrors, Polarimetry, Telescopes, Sensors, Space telescopes, Optical design, Spectral resolution, Ultraviolet radiation, Polarization, Optical components, Spectrographs, Freeform optics

Read Abstract +

Proceedings Article | 5 June 2018 Paper

Spectrographs with holographic gratings on freeform surfaces: design approach and application for the LUVOIR mission

Eduard Muslimov, Marc Ferrari, Emmanuel Hugot, Jean-Claude Bouret, Coralie Neiner, Simona Lombardo, Gerard Lemaitre, Robert Grange

Proceedings Volume 10690, 106901H (2018) https://doi.org/10.1117/12.2311887

KEYWORDS: Optical design, Spectrographs, Holography, Spectral resolution, Image quality, Freeform optics, Mirrors, Optical components, Diffraction gratings, Astronomical instrumentation

Read Abstract +

Showing 5 of 8 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years